阅读说明：本技术 热致变色沥青路面温度场及降温耐久性能的室内模拟方法 (Indoor simulation method for temperature field and cooling durability of thermochromic asphalt pavement ) 是由 于斌 彭炜智 黎威 刘士南 洪千哲 周曜迪 于 2019-11-18 设计创作，主要内容包括：本发明公开了一种热致变色沥青路面及温度场降温耐久性能的室内模拟方法,该方法包括以下步骤：(1)制备热致变色沥青路面试件；(2)将成型的三层路面结构需在周围及底部包裹隔温隔热材料；(3)分别在试件不同深度打孔作为传感器预留孔洞,在打好的传感器预留孔洞中装入六路传感器头,连接配备的传感器处理器,通过电脑导出各深度的温度变化趋势,即为温度场；(4)采用步骤(1)中制备的热致变色沥青路面试件进行降温耐久性能试验,所述的耐久性包括冻融循环老化,热老化、紫外老化。本发明做到了方便、控制精准和可重复性。(The invention discloses a thermochromic asphalt pavement and an indoor simulation method for temperature field cooling durability, which comprises the following steps: (1) preparing a thermochromic asphalt pavement test piece; (2) wrapping heat insulation materials around and at the bottom of the formed three-layer pavement structure; (3) punching holes at different depths of a test piece respectively to be used as sensor reserved holes, installing six sensor heads in the punched sensor reserved holes, connecting the sensor heads with a matched sensor processor, and deriving the temperature change trend of each depth through a computer to obtain a temperature field; (4) and (2) carrying out a cooling durability test by adopting the thermochromic asphalt pavement test piece prepared in the step (1), wherein the durability comprises freeze-thaw cycle aging, heat aging and ultraviolet aging. The invention achieves the advantages of convenience, accurate control and repeatability.)

1. A thermochromic asphalt pavement and an indoor simulation method for temperature field cooling durability are characterized by comprising the following steps:

(1) preparing a thermochromic asphalt pavement test piece, which comprises an upper surface layer, a middle surface layer and a lower surface layer, wherein the upper surface layer adopts thermochromic asphalt, the middle surface layer and the lower surface layer both adopt common SBS asphalt, the thickness of the upper surface layer is 4cm, the thickness of the middle surface layer is 6cm, the thickness of the lower surface layer is 8cm are formed by cutting after the upper surface layer and the lower surface layer are respectively formed, and the layers are bonded into a three-layer pavement structure by using emulsified asphalt;

(2) wrapping heat insulation materials around and at the bottom of the formed three-layer pavement structure;

(3) punching holes at different depths of a test piece respectively to be used as sensor reserved holes, installing six sensor heads in the punched sensor reserved holes, connecting the sensor heads with a matched sensor processor, and deriving the temperature change trend of each depth through a computer to obtain a temperature field;

(4) and (2) carrying out a cooling durability test by adopting the thermochromic asphalt pavement test piece prepared in the step (1), wherein the durability comprises freeze-thaw cycle aging, heat aging and ultraviolet aging.

2. The indoor simulation method for the cooling durability of the thermochromic asphalt pavement and the temperature field according to claim 1, wherein the freeze-thaw cycle aging test method in the step (4) is to perform freeze-thaw cycle on the upper layer according to the experimental regulations for road engineering asphalt and asphalt mixture (JTG E20-2011), and bond and form the upper layer after the freeze-thaw cycle to form a freeze-thaw cycle aging test piece; the thermal aging is to simulate sunlight by using an iodine-tungsten lamp to irradiate the formed thermochromic asphalt pavement test piece in the step (1), wherein the irradiation time is determined by three factors of the iodine-tungsten lamp power, the cross-sectional area of the formed test piece and the annual solar radiation amount of a road using area, and the thermal aging test piece is formed after the iodine-tungsten lamp is used for irradiation; the ultraviolet aging is to irradiate the pavement structure test piece formed in the step (1) by using an ultraviolet lamp under the real condition, wherein the irradiation time is determined by three factors of the power of the ultraviolet lamp, the cross-sectional area of the formed test piece and the annual ultraviolet radiation quantity of a road using area, and the ultraviolet aging test piece is formed after the ultraviolet lamp irradiates; taking the thermochromic asphalt pavement test piece prepared in the step (1) as a control group; and then comparing the freeze-thaw cycle aging test piece, the thermal aging test piece and the ultraviolet aging test piece with a control group respectively to obtain the cooling performance durability of the thermochromic asphalt mixture.

3. The indoor simulation method for the cooling durability of the thermochromic asphalt pavement and the temperature field according to claim 1, wherein the preparation method of the thermochromic asphalt for the upper layer in the step (1) is as follows:

① putting SBS pitch into oven, heating to melt completely, the oven temperature is 160 deg.C;

② adding the thermochromic powder into SBS pitch, and continuously shearing at 140-145 ℃ at a high temperature for 15-20 min at a shearing speed of 400-500 r/min;

③, putting the mixed asphalt into an oven to be stored for 1h at the temperature of 160 ℃ to obtain thermochromic asphalt;

④ obtaining the thermochromic asphalt after cooling at room temperature.

4. The indoor simulation method for the temperature-reducing durability of the thermochromic asphalt pavement and the temperature field according to claim 1, wherein in the step (3), the holes are punched at the depths of the test piece, namely, the depths of the test piece are 2cm, 4cm, 6cm, 8cm, 10cm and 12cm respectively, and the holes are reserved as sensors.

The technical field is as follows:

the invention relates to the field of asphalt pavement temperature field measurement and cooling performance durability, in particular to a thermochromic asphalt pavement temperature field and a cooling durability indoor simulation method.

Background art:

the asphalt pavement is used as a main surface layer form of a high-grade pavement in China, and has many advantages. However, due to the black pavement of the asphalt surface layer, the temperature of the pavement is too high in summer, and due to the viscoelastic-plastic property of the asphalt, under the repeated action of heavy load, diseases such as rutting and the like are easy to occur. Therefore, the high-temperature disease of the asphalt pavement can be actively avoided by reducing the temperature of the pavement in summer. The thermochromic asphalt has great prospect as a material capable of reducing the temperature of the pavement. However, since the actual cooling performance is required for cooling, it is difficult to achieve repeatability and control variables only by the test path and the actual environment.

Disclosure of Invention

Aiming at the problems, the invention provides an indoor simulation method for the temperature field and the cooling durability of the thermochromic asphalt pavement, which can be used for measuring the temperature field of the thermochromic asphalt pavement structure in an indoor environment, and can also repeatedly probe the influence of freeze-thaw cycles, thermal aging and ultraviolet aging on the cooling performance of the thermochromic asphalt pavement structure, so that convenience, accurate control and repeatability are realized.

The above purpose is realized by the following technical scheme:

the indoor simulation method for the cooling durability of the thermochromic asphalt pavement and the temperature field comprises the following steps:

(1) preparing a thermochromic asphalt pavement test piece, which comprises an upper surface layer, a middle surface layer and a lower surface layer, wherein the upper surface layer adopts thermochromic asphalt, the middle surface layer and the lower surface layer both adopt common SBS asphalt, the thickness of the upper surface layer is 4cm, the thickness of the middle surface layer is 6cm, the thickness of the lower surface layer is 8cm are formed by cutting after the upper surface layer and the lower surface layer are respectively formed, and the layers are bonded into a three-layer pavement structure by using emulsified asphalt;

(2) wrapping heat insulation materials around and at the bottom of the formed three-layer pavement structure;

(3) punching holes at different depths of a test piece respectively to be used as sensor reserved holes, installing six sensor heads in the punched sensor reserved holes, connecting the sensor heads with a matched sensor processor, and deriving the temperature change trend of each depth through a computer to obtain a temperature field;

(4) and (2) carrying out a cooling durability test by adopting the thermochromic asphalt pavement test piece prepared in the step (1), wherein the durability comprises freeze-thaw cycle aging, heat aging and ultraviolet aging.

The indoor simulation method of the cooling durability of the thermochromic asphalt pavement and the temperature field comprises the steps of (4) performing freeze-thaw cycle on the upper layer according to road engineering asphalt and asphalt mixture experimental regulations (JTGE 20-2011), and bonding and molding after the freeze-thaw cycle to form a freeze-thaw cycle aging test piece; the thermal aging is to simulate sunlight by using an iodine-tungsten lamp to irradiate the formed thermochromic asphalt pavement test piece in the step (1), wherein the irradiation time is determined by three factors of the iodine-tungsten lamp power, the cross-sectional area of the formed test piece and the annual solar radiation amount of a road using area, and the thermal aging test piece is formed after the iodine-tungsten lamp is used for irradiation; the ultraviolet aging is to irradiate the pavement structure test piece formed in the step (1) by using an ultraviolet lamp under the real condition, wherein the irradiation time is determined by three factors of the power of the ultraviolet lamp, the cross-sectional area of the formed test piece and the annual ultraviolet radiation quantity of a road using area, and the ultraviolet aging test piece is formed after the ultraviolet lamp irradiates; taking the thermochromic asphalt pavement test piece prepared in the step (1) as a control group; and then comparing the freeze-thaw cycle aging test piece, the thermal aging test piece and the ultraviolet aging test piece with a control group respectively to obtain the cooling performance durability of the thermochromic asphalt mixture.

The indoor simulation method for the cooling durability of the thermochromic asphalt pavement and the temperature field comprises the following steps of (1):

① putting SBS pitch into oven, heating to melt completely, the oven temperature is 160 deg.C;

② adding the thermochromic powder into SBS pitch, and continuously shearing at 140-145 ℃ at a high temperature for 15-20 min at a shearing speed of 400-500 r/min;

③ and putting the mixed asphalt into an oven to be stored for 1h at the temperature of 160 ℃ to obtain the thermochromic asphalt.

④ obtaining the thermochromic asphalt after cooling at room temperature.

In the indoor simulation method for the cooling durability of the thermochromic asphalt pavement and the temperature field, in the step (3), holes are punched at the positions of the test piece with the depths of 2cm, 4cm, 6cm, 8cm, 10cm and 12cm respectively to serve as reserved holes of the sensor.

Has the advantages that:

compared with the prior art, the invention has the following beneficial effects:

1. compared with the actual environment observation of a pavement temperature field, the method reduces labor waste and improves the precision and timeliness of observation;

2. compared with the existing asphalt pavement cooling durability test, the method shortens the test period, and is more flexible in simulation method;

3. the observation of the cooling durability of the asphalt pavement can effectively predict and relieve the urban heat island effect and reduce the high-temperature diseases of the asphalt pavement.

Drawings

FIG. 1 is a composition and molded structure of a thermochromic asphalt pavement structure of the present invention;

FIG. 2 is a top view of the molded wrapped insulation material;

FIG. 3 is a schematic view of a method for measuring the temperature of a thermochromic bituminous pavement structure.

Detailed Description

The invention is further explained below with reference to the drawings.

Referring to fig. 1, the indoor simulation method for the cooling durability of the thermochromic asphalt pavement and the temperature field of the invention comprises the following steps:

(1) the thermochromic asphalt pavement test piece is prepared, black thermochromic asphalt is used as an upper surface layer (SMA-13), and SBS asphalt is used as a middle surface layer (SUP-20) and a lower surface layer (SUP-25). The thermochromic asphalt is prepared from thermochromic powder and SBS. The preparation method comprises the following steps:

1) putting SBS pitch into a drying oven, heating to completely melt, wherein the temperature of the drying oven is 160 ℃;

2) adding the black thermochromic powder into SBS asphalt, and continuously shearing at the high temperature of 140-145 ℃, the shearing speed of 500r/min and the shearing time of 20 min;

3) and (3) placing the mixed asphalt into an oven to be stored for 1h at the temperature of 160 ℃ to obtain the black thermochromic asphalt.

4) Cooling at room temperature to obtain black thermochromic asphalt

The thermochromic powder is an organic compound, and when the temperature is higher than 31 ℃, the color becomes light to reflect more sunlight, and when the temperature is lower than 31 ℃, the thermochromic powder becomes dark, so that the self reflectivity is changed according to the ambient temperature, and the temperature is reduced.

The asphalt pavement structure comprises an upper surface layer (SMA-13), a middle surface layer (SUP-20) and a lower surface layer (SUP-25), wherein the upper surface layer asphalt is black thermochromic asphalt, and the middle surface layer and the lower surface layer asphalt are SBS asphalt. Respectively forming an upper surface layer, a middle surface layer and a lower surface layer, and bonding the upper surface layer (4 cm), the middle surface layer (6 cm) and the lower surface layer (8 cm) into a three-layer pavement structure by using emulsified asphalt through cutting.

In order to simulate the heating condition of a real road surface, only the upper surface layer is reserved for heat exchange with the outside. Therefore, the formed three-layer pavement structure needs to be wrapped with thermal insulation materials with the thickness of 2cm at the periphery and the bottom, and the wrapped thermal insulation materials are Zhisheng ZS-1091 type thermal insulation coatings.

The purpose of the three-layer pavement structure is to obtain a temperature field of the pavement structure, so that holes are needed to be punched at the positions of 2cm, 4cm, 6cm, 8cm, 10cm and 12cm of a test piece after the ZS-1091 type thermal insulation coating is wrapped, and holes are reserved for the sensors.

The formed thermochromic pavement structure is characterized in that six sensor heads are respectively inserted into reserved holes of 2cm, 4cm, 6cm, 8cm, 10cm and 12cm and connected with an LGR-WD61 sensor produced by Hangzhou Luge science and technology limited company, and the temperature change trend of each depth is derived through a computer.

The method for researching the durability of the cooling performance of the thermochromic asphalt pavement comprises freeze-thaw cycle aging, heat aging and ultraviolet aging.

The freeze-thaw cycle aging method is to carry out freeze-thaw cycle on the upper layer according to road engineering asphalt and asphalt mixture experimental regulations (JTGE 20-2011), and the upper layer is bonded and molded after the freeze-thaw cycle. The thermal aging is to simulate the sunlight irradiation by using a iodine-tungsten lamp according to a formed pavement structure, wherein the irradiation time is determined by three factors of the power of the iodine-tungsten lamp, the cross-sectional area of a formed test piece and the annual solar radiation of a road using area, and the test piece is irradiated by the iodine-tungsten lamp for later use. The ultraviolet aging is to simulate the ultraviolet irradiation under the real condition by using an ultraviolet lamp according to the formed pavement structure, wherein the irradiation time is determined by three factors of the power of the ultraviolet lamp, the cross-sectional area of a formed test piece and the annual ultraviolet radiation quantity of a road using area, and the formed test piece is irradiated by the ultraviolet lamp for later use.

And obtaining a pavement structure after freeze-thaw cycle aging, a pavement structure after heat aging and a pavement structure after ultraviolet aging, and simultaneously taking the pavement structure which is not subjected to aging treatment as a control group. The four pavement structures utilize six sensor heads to be respectively inserted into reserved holes of 2cm, 4cm, 6cm, 8cm, 10cm and 12cm and connected with a sensor processor, and the temperature change trend of each depth is derived through a computer.

The temperature reduction performance durability of the thermochromic asphalt mixture under various aging modes can be obtained by comparing the temperature of each thickness with that of a control group, and comparing the temperature of each thickness with different freezing-thawing cycle aging times, different iodine-tungsten lamp irradiation times and different ultraviolet lamp irradiation times.